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ObjectId

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  • Methods and Attributes
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ObjectId(<hexadecimal>)

Returns a new ObjectId value. The 12-byte ObjectId value consists of:

  • a 4-byte timestamp value, representing the ObjectId's creation, measured in seconds since the Unix epoch
  • a 5-byte random value generated once per process. This random value is unique to the machine and process.
  • a 3-byte incrementing counter, initialized to a random value

While the BSON format itself is little-endian, the timestamp and counter values are big-endian, with the most significant bytes appearing first in the byte sequence.

ObjectId() can accept the following parameter:

Field
Type
Description
hexadecimal
String
Optional. Hexadecimal string value for the new ObjectId.

ObjectId() has the following attribute and methods:

Attribute/Method
Description
str
Returns the hexadecimal string representation of the object.
Returns the timestamp portion of the object as a Date.
Returns the JavaScript representation in the form of a string literal "ObjectId(...)".
Returns the representation of the object as a hexadecimal string. The returned string is the str attribute.

To generate a new ObjectId, use ObjectId() with no argument:

x = ObjectId()

In this example, the value of x would be:

ObjectId("507f1f77bcf86cd799439011")

To generate a new ObjectId using ObjectId() with a unique hexadecimal string:

y = ObjectId("507f191e810c19729de860ea")

In this example, the value of y would be:

ObjectId("507f191e810c19729de860ea")

Access the str attribute of an ObjectId() object, as follows:

ObjectId("507f191e810c19729de860ea").str

This operation will return the following hexadecimal string:

507f191e810c19729de860ea
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